Handle MEDIA_CAPTION_TOO_LONG error

[ableev]

Originally reported in #9.

The problem: telegram bot api doesn't allow to add caption to the photo with length more than 200 symbols.

Current solution: message cuts to 200 symbols, warning to stdout, unable to get truncated part of message.

To discuss two ideas:

1. Split message in two parts: first one is the caption and has 200 symbols length, second one is the next part, sent after the first as plain text without graph.
2. Separate text and image if length is more than 200 symbols. The first message is graph, the second is plain text (or we can swap them).

What is best? Or any other ideas?

[ableev]

New idea. Today's update:

The Bot API now supports silent notifications. We've added an optional `disable_notification` parameter to all sending-related methods.
https://core.telegram.org/bots/api#available-methods

This means that it will be possible to send text message and graph right after that separately.
My problem is when script sends me a message with graph, I don’t see alert in my push messages, just “Zabbix Bot sent photo”.

[ableev]

Graphs are sending as reply-to messages with images only.